A population is a collection of all individuals of the same species at a specific time and in a specific natural area. For example, all grass carp in a pond, all giant pandas in a protected area and the total population of a town can be regarded as a population. Population is composed of individuals, but it has characteristics that biological individuals do not have.
Wetland is called "kidney of the earth", which provides a feeding ground for fish and birds. Fishery resources are abundant, which can absorb and store water resources, protect coastline and regulate climate ... Waterbirds are an important part of wetland biodiversity and an important biological indicator reflecting wetland health.
What migratory birds are there?
Migratory birds include cuckoo, swan, swallow, wild goose, swan goose, snow goose, black-necked crane, golden spotted owl, oriole and so on. Migratory birds can be divided into summer migratory birds and winter migratory birds:
Summer and winter migratory birds refer to flying to a certain area in summer and autumn to nest and live in peace. The bird has grown up, and it is probably early autumn. One by one, they flew to the warmest area in the south for the winter, and then flew to this area to breed in the following spring. For this area, this kind of bird is called summer and winter migratory bird.
For example, Golden Swallow spreads all over China in summer and migrates to southern Yunnan, Hainan Province, Nansha Islands and Taiwan Province Province in winter. Rhododendron and oriole are an example. They are both migratory birds in summer.
Winter migratory birds refer to winter migratory birds who spend the winter in a certain area and fly to the northern area to breed in the following spring. When the young birds grow up, they fly to their original areas for the winter in early autumn. For this area, this kind of bird is called winter migratory bird. In the Yangtze River in China, geese, swans and ducks are winter migratory birds.